Countersinking-drill.



11 1 2% A 1.11. DARLING, 1R. GOUNTERSINKI-NG DRILL,

APPLICATION FILED OUT. 21, 1911. LUWALQSG Patented Au 19, 1913.

- new on an enlarged scale looking'toward the drill point. Fig; 3 is anenlarged detail ALBERT C. DARLING, JR., F YORK.

eounrnnsmmnenmm.

Specification of Letters latent. I

Patented Aug. 19, 1913.

' Application filed October 21, 1911. Serial No.-655,947.

To all whom-it may concern Be it known'that I, ALBERT C. DAnLrNG, J r.,a citizen of the United States, residing at Lodi, in the county of.Seneca and State 'of New York, have invented new and useful Improvementsin Countersinking-Drills, of

" union 9 of angular form in cross section for Y which .the following'isa specification.

.This' invention relates to countersinking drills especially designedfor forming bolt or rivet holes vin the rims and tires of, vehicleWheels, the object of theinvention being to provide'a simple,inexpensive and efficient one-piece drill, whereby alined holes maybesimultaneously bored in a tire and v rim and the rim hole countersunk ina single continuous operation. L I A further object of the invention isto provide-a single-piece double'drill embodying in one and the sametool drills of differentdiameters which maybe interchangeably employedby simply reversing the, tool end for end, thus obviating thenecessity'of using separate or take-apart tools.

The invention consists of the features of construction, comblnation andarrangementof parts hereinafter fully described and claimed, referencebein embodying my invention. Fig; 2 is an end section on-line 3--3 ofFi 1. Fig. 4 isa side view ofa single dril embodying the 'lnVGIltlOIl. I

. Referring tothe drawing 1 represents terminating in a tapering outerend '2, from which projects a spiral drill bit 3, which bitis integralwith the body or shank, and of relatively" smaller diameter than thesame. This bit is provided with the usual drill oint 4, and

' spiral cutting edge 5.- The'bo' y or shank 1 is formed adjacent to itstapered end 2' width and depth therefrom. These grooves form clearancechannels and the outer ends of the rear walls of the grooves terminatein cutting'edge's 7 formed by beveled S11 Ifhad to the accompanyingdrawing, in w ich:

Figure 1 is aside view of a double drillfaces 8 which beveled surfacescollectively produce the tapering form fof the end 2.

In Fig. 1,1 have shown adouble drill of the character described, theshanks of the drills being arranged in longitudinal 'alinement; andconnected at their inner ends by a engagement with the chuck of asuitable driving tool. The drills andunion are formed ofia single solidpiece of metal in a unitary structure so that by simply reversing thetool end for endeither one of the drills may beemplo ed. Preferably thedrills are made of di erent sizes or diameters so that by the use of asingle tool, holes of difl'erent diameters may be bored or countersunk.This construction secures economy 0f manufactureas well as convenienceof use and operation, as the necessity of employ-' ing a take-apartconstruction or independent tools for viated.

Fig. 4 shows a single vdrill constructed in accordance with theinvention. The drill is especially designed for the purpose offorming'the bolt or rivet receiving holes in the rims and tires-ofvehicle wheels and countersinking the holes in the rims. By means of thebit 3 alining hpl'es'in the tire and rim.

As a new and improved article of manufacture, a countersmking drillcomprising a body or shank having a conical outer en a drill bit havinga'smooth surfaced ortion integral with and of less diameter t an theconical end of the shank and projecting 1 from the apex thereof, saidshank being provided with an annular series of compara-.

tivelyglong, gently inclined substantially obtuse-angledtriangular-shaped spiral grooves.

opening through the conical end of the the purposes set forth is obshankand gradually increasingiin width countersinki'ng, cutters mergingdirectly 10 and depth toward the same, each of said into the face of'thesmooth portion of the grooves. having front and rear relatively drillbit. I

long and short beveled side walls respec- In testimon whereof I aflix mysignature tively inclined at obtuse and oblique angles in presence 0 twowitnesses. to the axis of the bit, the said rear or ALBER T G. DARLING,JR. shorter walls of the grooves bein undercut- Witnesses:

and arranged to provide with t e beveled" S. MAUD Mm,

surfacesiof the conical portion a series of RICHARD FARR.

